Valve and actuating means for fluid motors



A ril 21, 1953 P. B. DAMGAARD VALVE AND ACTUATING MEANS FOR FLUID MOTORS F iled Feb. 4, 1948 FIG. 2

FIG.. 1'

Patented Apr. 21, 1953 UIYUNITED STATES PATENT OFFICE VALVE AND YACTUATING MEANSFOR FLUID 1 MOTORS a I Poul Bjorn Darngaard, Copenhagen, Denmark Application February 4, 1948, Serial No. 6,311

' i In Denmark February 8, 1947 This invention relates to irrigating devices employed for watering relatively large areas by overhead spraying, Such as are used: by market gardeners or farmers for watering crops or by those responsible for the upkeep of tennis lawns and the like. 7 i I 1 Many such devices have been proposedin the past H which comprise an element carrying one ormore spraying nozzles andcaused to rotate by the action or reactionof the water supplied to or leaving the nozzles, but these are not entirely satisfactory in that the water is distributed over a more or less circular area with a greater deposition near the centre than near the outer edge. It is also known to provide relatively long and substantially horizontally disposed pipes or tubes formed with spraying apertures along their length, hydraulic motors being provided for oscillating the pipes about theirown axes in order-to spray more-or-less rectangular areas with ahigher degree of uniformity. The hydraulic'motors have been operated by the water under pressure supplied to the spraying pipes but, as heretofore proposed, they have been relatively complicated in construction, easily damaged and entail correspondingly high upkeep costs. e

The present invention has for its main object to provide an improved hydraulic motor for irrigating devices of the last-mentioned character which shall be of a robust and simple construction that will be efiicient in operationand require but little maintenance.

Accordingly, this invention consists in a hydraulic motor supplied with water from the same source as thespraying device and adapted to be operatively oonnectedto the latter to cause the oscillation thereof, wherein the motor comprises a cylinder, adouble-acting' piston working therein, valve means mounted on the piston rod to direct thefsupply of water to the one or other end of the cylinder and simultaneously to place the opposite end of the-cylinder in communication with a discharge opening, and means actuated by relative motion between the piston and the cylinder for operating the valve means from one setting to another as the piston reaches a predetermined point in its stroke.

the flow of water formed through the piston rod and each opening to the respective side of the piston within the cylinder.

In order that the invention may be clearly understood, there will now be described one example of the way in which it may be carried into effect, reference being made to the accompany-ing somewhat diagrammatic drawings, wherein: I .Eis. s ;a xia se ti nihrqus h d au 1 Claim. 1 (or. 121- 50) motor according to the invention, part of the valve means being sectioned on a slightly difierent plane and the spraying device with its connection to the motor being omitted, and

Fig. 2 is an elevation of the motor shown in Fig. 1.

The hydraulic motor shown comprises (see Fig. 1 a cylinder l within which works a double-- acting piston 2 secured on the inner end of a tubular piston rod 3, the passage through the rod opening to the face of the piston which is exposed to the cylinder-chamber 4 at one side of the piston. The piston rod 3 is secured at its outer end in a bore formed in the body 5 of a multi-way cock, passing through a larger diameter aperture in this body in which is secured the outer end of a tube 6 that surrounds the tubular piston rod 3 with considerable clearance and is secured at its inner end to the piston 2.

Within the body 5 of the multi-way cock is formed a circularly extending passage 1 which is in free communication at one point with the annular passage left between the tubular piston rod 3 and the tube 6, and, through this passage and an aperture 8 formed in the inner end of the tube 6, is thus in free communication with the cylinder-chamber 9 at the side of the piston 2 remote from the chamber 4. At a point opposite to its connection with the annular passage between the parts 3 and 6, the passage 1. is placed in free communication, by way of a passage Hl, with a central chamber H formed in the body 5 to accommodate a plug member l2 capable of oscillation from the position shown in full lines in Fig. 1 to the position shown in broken lines in that figure. In the first orfullline position of the plug member l2, the passage I0 is placed in freecommunication with a passage I3 formed in the body 5 to lead from the outer surface thereof into the chamber II but passing to one side of the passage 1. At the same time, the interior of the tubular piston rod 3 is placed in free communication with a passage I4 also formed in the body 5 to lead from the outer surface thereof into the chamber H but again passing to one side of the passage 1, it being understood that the bore in which the piston rod 3 is secured leads into the chamber ll diametrically opposite to the passage llland that the passages l3 and I4 are also diametrically opposed.

In the second or broken-line position of the plug member 12, the passages 10 and I4 are placed in communication with each other while the passage I3 is placed in communication with the bore leading to the interior of the tubular piston rod 3. I

- Pipes (not shown) are connected one to the uie s d g saqhp he. Pass s "a and one pipe (assumed to be that connected to the passage l3) supplying water under pressu e, and

by an arm and link to the body 5 of the multiway cock, in which case the cylinder I would be fixed and the pipes would be of a flexible character, or may be connected to the cylinder I, in which case the body 5 would be fixed. and only the pipe leading therefrom to the inlet. of the spraying device need be flexible.

Referring now to Fig. 2, the plug member 12 is fixedly mounted on a spindle l5 which extends outside the body 5 to have mounted thereon the inner ends of an arm i6 and an arm H, the former being secured on the spindle and the la ter being freely rotatable thereon. In their positions corresponding to the full-line position of the plug member I2 in Fig. 1 (see the full linesin Fig. 2), the arms-l5 and 17 extend to opposite sides of a plane containing the axes of both the cylinder l and the spindle [5 but to the same side of a plane at right-angles to the said plane and passing through the spindle axis. The outer ends of the arms [6 and l! are connected by a tension spring [8 and the outer end of the arm I! is also connected by a rigid link id to a fixed point, as shown, to the adjacent end 20 of the cylinder The full-line position of the arm is is determined by a stop, such as that shown at 2|, and a second stop, such as that shown at 22, serves to arrest the arm It in its dotted-line position Hia (Fig. 2) corresponding to the dottedline position of the plug member l2 shown in Fig. 1 The arm i is displaced with a snap action between its extreme positions due to movement of the arm H and the consequent displacement of the line of action of the spring l8 beyond the axis of the spindle l5, as will be understood.

In the operation of the device described, the

piston 2 being assumed to be at the end of its.

one stroke in which the parts are in the fullline positions shown, water under pressure supplied through passage 13 flows through passages l0 and T- and tube 0 to the cylinder-chamber 9 and forces the piston 2 away from the end 20 of the cylinder, theWa-ter in the chamber 4 meanwhile being delivered by way of the tubular piston rod 3; and passage i lto the spraying device. The piston continues to move relative to the cylinder, causing the spraying device to swing on its axis and the body with the spindle it to move towards the cylinder-end 2%, until the position of the arm H relative to the arm 15 is that indicated at Ha in Fig. 2, whereupon the spring 3 causes the arm it to move rapidly to the position shown at leain Fig. 2.

As the flow of water into and out from the chambers and 9 is now reversed, the piston 2 immediately reverses its direction of travel and continues to move towards the end 20 of the cylinder until the motion of the spindle 15 relative to the arm I7 causes the arm 10 to be snapped over into its full-line position again, whereupon the above-indicated cycle is repeated continuously so long as water under pressure is supplied to the passage I3.

The spraying device is therefore continuously oscillated on its axis so that the line along which the jets, of water issuing therefrom strike the ground is caused to sweep backwards and forwards across the area being irrigated while remaining substantially parallel with the axis of the spraying device.

It will be seen that the motor described is extremely simple and robust in construction and has very few moving parts while requiring but the minimum of; pipe connections.

What I claim is:

An automatically reversing hydraulic reciprocating motor comprising a cylinder, a doubleacting piston; working in the cylinder, a piston rod. connected at one end to the piston and extending at its other end externally of the cylinder, a first passage formed through the piston rod to open to one working face of the piston, a second passage formed through the piston rod to open to the other working face of the piston, a valve body fixedly mounted on the piston rod externally of the cylinder, an inlet for admitting fluid under pressure to said valve body, an outlet exhausting fiuid from said valve body, a

sag-e formed in the valve body to establish com-v munication between said inlet and said chamber, a second passage formed in the valve body to establish communication between said outlet and said chamber, a third passage formed in the valve body to establish communication between the second passage in the piston rod and said chamber, a fourth passage formed in the valve body to establish communication between the first passage in the piston rod and said chamber, a valve element rotatably mounted within said chamber and having a part extending to theexterior of the valve body, an actuating arm secured on said part of the valve element, stop means mounted on thevalve body to co-operat with said arm in defining two spaced limiting'positions of said valve element, a second arm pivotally mounted on the valve body, a link articulatedly connecting the second arm to the cylinder whereby reciprocating motion of the piston relative to the cylinder will cause the second arm to rock to-and-fro about its pivot, and

snap spring means connecting the actuating arm and said second arm so that the actuating arm is moved rapidly against each of the stop means in alternation as the second arm executed its rocking motion, the valve element in one limiting position establishing communication between the first and third passages in the valve body and betwee he. e nd nd. ur h as es n h valve body, and in the other limiting position establishing communication between the first and f ur h p ss e the valve bo a d e we n the. seccnsi. nd l rd a a s. in h valve body. 7

- L BJo AM AABD References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 892,531 Lewis July 7, 1908 897,433 Wagner et a1. Sept. 1, 1908 963,581 Kel'so July 5, 1910 1,258,337 Imblum' Mar. 5, 1918 1,454,332 Norton May 8, 1923 2,059,016 Newton Jan. 26, 1937 2,124,797 Rust et al July 26, 1938 FQREI N P TENTS Number Country Date.

17,720 Great Britain Oct. 26, 1887 174,467 Germany Sept. 4, 1906 

